Leukocyte adherence inhibition: an automated microassay demonstrating specific antigen recognition and blocking activity in two murine tumor systems.

This communication describes an automated micro-adherence inhibition assay. Tumor-specific immunity was demonstrated with B16 melanoma and MCA-38 colon adenocarcinoma, both of which are syngeneic to the same strain of mouse (C57B16/J). Abrogation of the leukocyte adherence inhibition (LAI) response of sensitized leukocytes has been demonstrated in the MCA-38 tumor system by the addition of serum from mice bearing MCA-38 progressively growing tumors, a property not present in normal serum. The sensitivity of the system has also been demonstrated by showing that LAI will change prior to a tumor becoming palpable. This microassay has the advantage of being simple, rapid and reproducible, and involves the use of minimal quantities of antigenic preparations and leukocytes, and in addition is amenable to rigorous statistical analysis.